from flask import Flask, render_template, request, redirect, url_for, session, abort
from datetime import datetime, timedelta
import numpy as np
from dateutil.relativedelta import relativedelta
import os

app = Flask(__name__)
app.secret_key = os.environ.get('SECRET_KEY', 'dev-key')

# HTML-Template wird jetzt aus templates/index.html geladen

WOCHENTAGE = ["Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samstag", "Sonntag"]

@app.route('/', methods=['GET', 'POST'])
def index():
    # Rudimentäres Logging für Page Impressions
    log_dir = 'log'
    os.makedirs(log_dir, exist_ok=True)
    with open(os.path.join(log_dir, 'pageviews.log'), 'a', encoding='utf-8') as f:
        from datetime import datetime as dt
        f.write(f"{dt.now().isoformat()} PAGEVIEW\n")
    tage = werktage = wochentag = datumsrechnung = werktagsrechnung = kw_berechnen = kw_datum = wochen_monate = None
    active_idx = 0
    if request.method == 'POST':
        action = request.form.get('action')
        # Funktions-Logging
        with open(os.path.join(log_dir, 'pageviews.log'), 'a', encoding='utf-8') as f:
            from datetime import datetime as dt
            f.write(f"{dt.now().isoformat()} FUNC: {action}\n")
        if action == 'tage':
            active_idx = 0
            start = request.form.get('start1')
            end = request.form.get('end1')
            try:
                d1 = datetime.strptime(start, '%Y-%m-%d')
                d2 = datetime.strptime(end, '%Y-%m-%d')
                tage = abs((d2 - d1).days)
            except Exception:
                tage = 'Ungültige Eingabe'
        elif action == 'werktage':
            active_idx = 1
            start = request.form.get('start2')
            end = request.form.get('end2')
            try:
                d1 = datetime.strptime(start, '%Y-%m-%d')
                d2 = datetime.strptime(end, '%Y-%m-%d')
                if d1 > d2:
                    d1, d2 = d2, d1
                werktage = np.busday_count(d1.date(), (d2 + timedelta(days=1)).date())
            except Exception:
                werktage = 'Ungültige Eingabe'
        elif action == 'wochentag':
            active_idx = 2
            datum = request.form.get('datum3')
            try:
                d = datetime.strptime(datum, '%Y-%m-%d')
                wochentag = WOCHENTAGE[d.weekday()]
            except Exception:
                wochentag = 'Ungültige Eingabe'
        elif action == 'datumsrechnung':
            active_idx = 3
            datum = request.form.get('datum4')
            tage_input = request.form.get('tage4')
            richtung = request.form.get('richtung4')
            try:
                d = datetime.strptime(datum, '%Y-%m-%d')
                tage_int = int(tage_input)
                if richtung == 'add':
                    result = d + timedelta(days=tage_int)
                else:
                    result = d - timedelta(days=tage_int)
                datumsrechnung = result.strftime('%d.%m.%Y')
            except Exception:
                datumsrechnung = 'Ungültige Eingabe'
        elif action == 'werktagsrechnung':
            active_idx = 4
            datum = request.form.get('datum5')
            tage_input = request.form.get('tage5')
            richtung = request.form.get('richtung5')
            try:
                d = datetime.strptime(datum, '%Y-%m-%d').date()
                tage_int = int(tage_input)
                if richtung == 'add':
                    result = np.busday_offset(d, tage_int, roll='forward')
                else:
                    result = np.busday_offset(d, -tage_int, roll='backward')
                werktagsrechnung = np.datetime_as_string(result, unit='D')
                # Formatierung auf deutsch
                dt = datetime.strptime(werktagsrechnung, '%Y-%m-%d')
                werktagsrechnung = dt.strftime('%d.%m.%Y')
            except Exception:
                werktagsrechnung = 'Ungültige Eingabe'
        elif action == 'kw_berechnen':
            active_idx = 5
            datum = request.form.get('datum6')
            try:
                d = datetime.strptime(datum, '%Y-%m-%d')
                kw = d.isocalendar().week
                kw_berechnen = f"KW {kw} ({d.year})"
            except Exception:
                kw_berechnen = 'Ungültige Eingabe'
        elif action == 'kw_datum':
            active_idx = 6
            jahr = request.form.get('jahr7')
            kw = request.form.get('kw7')
            try:
                jahr = int(jahr)
                kw = int(kw)
                # Montag der KW
                start = datetime.fromisocalendar(jahr, kw, 1)
                end = datetime.fromisocalendar(jahr, kw, 7)
                kw_datum = f"{start.strftime('%d.%m.%Y')} bis {end.strftime('%d.%m.%Y')}"
            except Exception:
                kw_datum = 'Ungültige Eingabe'
        elif action == 'wochen_monate':
            datum = request.form.get('datum8')
            anzahl = request.form.get('anzahl8')
            einheit = request.form.get('einheit8')
            richtung = request.form.get('richtung8')
            try:
                d = datetime.strptime(datum, '%Y-%m-%d')
                anzahl_int = int(anzahl)
                if richtung == 'sub':
                    anzahl_int = -anzahl_int
                if einheit == 'wochen':
                    result = d + timedelta(weeks=anzahl_int)
                else:
                    result = d + relativedelta(months=anzahl_int)
                wochen_monate = result.strftime('%d.%m.%Y')
            except Exception:
                wochen_monate = 'Ungültige Eingabe'
    return render_template('index.html', tage=tage, werktage=werktage, wochentag=wochentag, datumsrechnung=datumsrechnung, werktagsrechnung=werktagsrechnung, kw_berechnen=kw_berechnen, kw_datum=kw_datum, active_idx=active_idx, wochen_monate=wochen_monate)


@app.route('/stats', methods=['GET', 'POST'])
def stats():
    stats_password = os.environ.get('STATS_PASSWORD', 'changeme')
    if 'stats_auth' not in session:
        if request.method == 'POST':
            if request.form.get('password') == stats_password:
                session['stats_auth'] = True
                return redirect(url_for('stats'))
            else:
                return render_template('stats_login.html', error='Falsches Passwort!')
        return render_template('stats_login.html', error=None)
    # Auswertung der Logdatei
    log_path = os.path.join('log', 'pageviews.log')
    pageviews = 0
    func_counts = {}
    if os.path.exists(log_path):
        with open(log_path, encoding='utf-8') as f:
            for line in f:
                if 'PAGEVIEW' in line:
                    pageviews += 1
                elif 'FUNC:' in line:
                    func = line.split('FUNC:')[1].strip()
                    func_counts[func] = func_counts.get(func, 0) + 1
    return render_template('stats_dashboard.html', pageviews=pageviews, func_counts=func_counts)


if __name__ == '__main__':
    app.run(debug=True)